Judge James Vaughn issued a directive Thursday saying he didn't believe a blanket stay of drug cases was warranted. But he also said that for trials scheduled for March involving evidence submitted to the testing lab, continuances will be granted upon prosecutors' request.

Authorities have identified at least 21 cases dating to 2010 in which drug evidence appears to be tampered with, substituted or gone missing after being submitted to the state medical examiner office's Controlled Substances Laboratory.

Testing at the lab, which handles about 6,000 drug evidence cases a year, has been suspended.